a) Give a balanced equation for the complete combustion of butane, b) Explain how this would change if there was insufficient oxygen present, and explain the problems this causes

C₄H₁₀ + 6.5O₂ -> 4CO₂ + 5H₂O
If there is not enough oxygen, incomplete combustion will occur, so CO (carbon monoxide) will be formed, carbon will form soot, and unburnt hydrocarbons will be released.This is dangerous as CO is a toxic gas.Also, soot causes global dimming.